The best definition of a safety barrier can be found in an article by Sklet from 2006:
Safety barriers are physical and/or non-physical means planned to prevent, control, or mitigate undesired events or accidents.
This definition has an interesting word. Planned. It implies that besides stopping unwanted events, a barrier is also organised formally. But by only looking at formal barriers, two aspects of safety are left out.
First, because we're excluding informal barriers. Someone that happens to walk on the beach and saves a drowning child is not a barrier because it hasn't been formally organised, while a lifeguard that does the exact same thing is considered a barrier. It's the combination of formal and informal barriers that keeps an organisation safe. They complement each other. However, if we measure the safety in an organisation, the focus is often put on formal barriers because they're easier to measure. This creates a blind spot for the informal side of safety. To prevent this, concepts like HRO (High Reliability Organising) and resilience engineering aim to strengthen our ability to deal with scenarios even if we haven't planned for them.
Second, there are many formal systems whose goal isn't to improve safety, but do so as a byproduct. Things like simplifying a proces to save costs, or a teambuilding exercise. If we didn't plan these things to increase safety, they're not considered barriers and aren't treated as such, event though they might have a positive effect.
In the end, there are many factors, both formal and informal, that increase safety in an organisation. The question is why do we even want to consider some of them as barriers? The reason is that we have to focus our efforts. If we think everything is important, it's hard to know where to start improving. Barriers are one way to focus on those parts of the formal organisation that are important to reduce our risks.
But once you're confident that all those formal barriers are working, don't think you're done. It's time to widen your view and look at the rest of the formal and informal factors that keep your organisation safe.Photo by Margarida CSilva on Unsplash